1. Field of Invention
The present invention relates generally to downhole oilfield tools and methods of use, and more specifically to downhole oilfield tools having two or more fluid injection ports for logging pressure, temperature, and/or fluid flow.
2. Related Art
It may be appreciated that well stimulation processes and systems have been in use for years. Typically, stimulation diversion processes and systems are comprised of downhole production logging tools (PLT), radioactive tracers with gamma ray detection tools and fiber optic strings measuring distributed temperature. These measurements in the PLT usually have single pressure, single flow meter, gamma ray and temperature. The data from these downhole tools are realtime when an electric cable and/or fiber optic fiber is connected inside the coiled tubing string, or in memory mode when the data is collected after the job.
Acidizing stimulation with coiled tubing may be effective if the acid can be placed in the correct targeted zones in the formation. The first step in accomplishing this is to determine the zone that would normally take the acid. Unfortunately, there is no current method of calculating this a priori or measuring placement during the job, and it is not possible to carry out production logging to measure the injectivity while pumping acid as the reactive fluid will continuously alter the injection conditions and profile. Other methods such as differential temperature sensing (DTS) to determine the well profile while pumping cold fluid are possible but have their own drawbacks.
From the above it is evident that there is a need in the art for improvement in monitoring oilfield fluid diversion systems and methods. In particular, it would be an advance in the art if downhole methods and systems could be devised wherein the tools and/or coiled tubing and DTS sensors are kept stationary the fluid injection point is changed to obtain two or more distinct logs. Alternatively, it would be advantageous if the fluid injection point is moved while point pressure is detected. With the help of these multiple logs, determination of the location of a thief zone would be feasible.